Forced air flow unit air-heating furnace



Dec. 9, 1952 J. ZlNK 2,620,787

FORCED AIR. FL'cw UNIT AIR-HEATING FURNACE FiledOct. .28, 1946 3: FIG. I

Zmventor JOHN s. ZINK,

Patented Dec. 9, 1952 UNITED STATES PATENT OFFICIE FORCED AIR FLOW UNIT AIR-HEATING FURNACE The present application is a continuation-inpart of my application Serial No. 650,865, filed February 28, 1946, which application has now become abandoned. i

This invention relates to unit heaters, and more particularly to a gas-fired unit for heating large spaces by the use of relatively great volumes of gas supplied to a relatively small unit.

In the use of gas-fired unit heaters for space heating, the heater is usually suspended from the ceiling of the building space to be heated. In many instances, the head room space of the building is such as to preclude the use of a unit heater large enough to provide suflicient volume of heated air, such. as is required to heat the space. Present day designs of suspended unit heaters do not permit the burning of large volumes of gas in a relatively small unit because the products of combustion are only permitted to flow in one direction from the burner.

It is, therefore, an important object of this invention to provide a unit gas heater wherein the products of combustion are directed in a counter-current flow to heat relatively large surfaces in a relatively small unit so as to increase the overall capacity and cause a greater delivery of heated air.

Another object is to supply a unit gas heater for the space heating of buildings and the like wherein an increased volume of heated air is provided with a minimum of head room utilized in the space to be heated.

Still another object is to furnish a gas unit heater for producing large volumes of warm air for space heating, which heater is simple in construction, eificient in operation, and durable in use.

With the foregoing objects outlined and'with other objects in view which will appear as the description proceeds, the invention consists in the novel features hereinafter described in detail, illustrated in the accompanying drawings, and more particularly pointed out in the appended claims.

In the drawing:

Fig. 1 is a vertical longitudinal sectional view of one embodiment of the invention.

Fig. 2 is a transverse vertical sectional view of the unit shown in Fig. 1, taken on the line 2-2 of that figure.

Referring to the embodiment of the invention illustrated in Figs. 1 and 2, l designates a tubular housing or casing which may be of cylindrical form to accommodate concentric spaced 2 Claims. (Cl. 126-11t cylinders ll, l2 and [3. The part [3 is centrally arranged in the housing In and forms a combustion chamber l4 closed at one end IE, but provided at its opposite end with a plurality of air intake tubes l6 converging toward the axis of the housing. The intake tubes are rigidly united with a conical member or wall I! which closes the inlet end of the combustion chamber and is provided at its apex I8 with an opening for the reception of a fuel burner is supplied with gas or other fuel, by means of a pipe 20. The cone functions to direct air into the space between cylinders l2 and IS. The tubes [6 project outwardly from the conical wall I1 and normal thereto and terminate at their outer ends beyond the circumference of the cylinder I3. The tubes l6 converge at their inner ends so as to direct air streams into the combustion chamber adjacent the fuel burner.

At the inlet end of the housing It), a fan 2| is arranged for blowing air through the housing and, into the combustion chamber, through the tubes I 5, and such fan may be driven by a motor 2| or.

Short tubes 22 connect the cylinders 12 and I3 near the closed end l5 of the combustion chamber for the purpose of discharging the gases of combustion into a convection chamber 23 provided by the cylinders II and I2. These cylinders are spaced apart and the ends of the convection chamber are closed by rings or walls 24 and 25, and the space within the convection chamber is obstructed by semi-circular baflies 26. 21, and 28, the baffles 26 and 21 having their ends extending downwardly, as shown at 29 in Fig. 2, and the baiiie 28 having its ends extending upwardly, as indicated at 30 in this figure. Due to this arrangement of bafiles, it will be obvious that the gases of combustion in travelling through the convection chamber will be caused to flow in a circuitous path or paths, as they move toward the stack 3|, which extends from the discharge end of the convection chamber through the top of the housing I0.

Spacers 32 are provided between the housing and the cylinder II, at the discharge end of the casing for holding the cylinders It and H in spaced relation.

In operation, it will be understood that the air to be heated will be forced through the passageway formed Within the cylinder Ill and it will travel along the exterior of the combustion chamber and along the inner and outer walls l2 and i l of the convection chamber before being discharged from the casing at the end where the struts 32 are located. At the same time, a large volume of gas will be supplied to the burner l9, and some of the air will be forced through the converging tubes I6 so as to impinge against the stream of fuel issuing from the burner nozzle. The gases of combustion will travel through the combustion chamber M in one direction, then radially through the tubes 22, and afterwards in the opposite direction through the convection chamber 23, and finally out of the stack 3!. In this way, a large volume of air can be heated by a relatively small heating unit because the hot gases of combustion are caused to travel counter-current while the air travels directly through the passageway formed by the housing [0.

It will be evident from the foregoing that air is forced through a passageway wherein it is heated by products of combustion passing first through a combustion chamber in one direction and then through a convection chamber in the opposite direction.

It is manifest that the essential elements of the invention are made of any good heat-conducting metal, and it is evident thatsuchmetal may be shaped to radiate maximum heat to the air passing through the unit.

While I have disclosed what I now consider to be a preferred embodiment of the invention in such manner that the same may be readily understood by those skilled in the art, I am aware that changes may be made in the details disclosed, without departing from the spirit of the invention, as expressed in the following claims.

What I claim and desire to secure byLetters Patent is:

1. In a unit space heater, an elongated cylindrical shaped tubular housing adapted to be supported in a substantially horizontal position, a cylinder of smaller diameter arranged within said housing and with the axis thereof substantially in alignment with the axis of the housing providing a combustion chamber, means closing one end of said cylinder, a conical wall closing the other end of said cylinder with an apex thereof directed outwardly of the cylinder, a fuel burner mounted in the apex portion of'said conical wall, a plurality of tubes mounted on said conical wall converging towards the axis of the housing for directing air into the combustion chamber, a second cylinder within said housing surrounding the first cylinder concentrically thereof and forming an annular space around the combustion chamber, a third cylinder mounted within said housing spaced around the second cylinder and spaced from the cylindrical housing, closure means joining common ends of the second and third cylinders, closure means joining the other ends of the second and third cylinders to provide a convection chamber, a plurality of radially disposed tubes connecting the combustion chamber with the convection chamber at an end remote from said fuel burner, a flue stack extending through the housing and in open communication with the convection chamber at an end adjacent the fuel burner, means for directing air against said conical wall to guide air into the annular space between the first and second cylinders and into the annular space between the third cylinder and the housing, a hemi-circular shaped baffle within the convection chamber joining the second and third cylinders, and a second hemicircular shaped baflle within the convection chamber joining the second and third cylinders and disposed in a diametrically opposite position with reference to the first bafile.

2. In a unit space heater, an elongated cylindrical shaped tubular housing adapted to be supported in a substantially horizontal position, a cylinder of smaller diameter arranged within said housing with the axis thereof substantially in alignment with the axis of the housing providing a combustion chamber, means closing one end of said cylinder, a conical wall closing the other end of the cylinder with an apex thereof directed outwardly of the cylinder, afuel burner mounted in the apex portion of said conical wall, a plurality of tubes projecting substantially normal to said conical wall terminating at their outer ends beyond the circumference of said cylinder and converging at their inner ends towards the axis of the cylinder to direct air streams into the combustion chamber adjacent the burner, a second cylinder within said housing surrounding the first cylinder concentrically thereof and forming an annular space around the combustion chamber, a third cylinder mounted within said housing spaced around the second cylinder and spaced from the cylindrical housing, closure means joining common ends of the second and third cylinders, closure means joining the other ends of the second and third cylinders to provide a convection chamber, a plurality of radially disposed tubes connecting the combustion chamber with the convection chamber at an end remote from said fuel burner, a flue stack extending through the housing and in open communication with the convection chamber at an end adjacent the fuel burner, and means for directing air against said conical wall to guide air into the annular space between the first and second cylinders and into the annular space between the third cylinder and the housing.

JOHN S. ZINK.

REFERENCES CITED' The following references are of record in the file of this patent: 

